Arm Mbed and Pelion Device Management support forum

Mbed OS 6 and low resource platforms

Whats the plan for the smaller target MCU’s that would normally use uARM library.
32K or less Flash MCU’s for instance.
Will these be dropped from Mbed?

Hi Paul, good question. Under the Version 6.0 preview Documents MBED are still listing the ‘Bare Metal’ as an option for resource limited devices
https://os.mbed.com/docs/mbed-os/v6.0-preview/reference/mbed-os-bare-metal.html

Hopefully that will transpire :slight_smile:

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Hi Paul, I switched lately from mbed-os 2 to mbed os 5 with “Bare-Metal”, this works pretty good for me and even needs about 25% less flash sizes compared to mbed-os 2. I am using the STM32L433 MCU series, I believe a 20k SRAM and 128k Flash are the minimum requirements for mbed-os projects.

Thanks Helmut,

I have tried os5 and added some changes to the .json file to this:

{
    "requires": ["bare-metal"],
    "target_overrides": {
        "*": {
            "target.boot-stack-size": "0x800",
            "target.printf_lib": "minimal-printf",
            "platform.minimal-printf-enable-floating-point": "false",
            "platform.stdio-minimal-console-only": true
        }
    }
}

and this I found somewhere else…

Then you need to modify mbed-os/targets/targets.json: find your target and replace ‘default_lib’ with ‘c_lib’ (small must be used).

However I can’t get the KL05z target to compile as it does on os2 rev.133.
This was the latest os2 version that would fit my code in.

But I think the answer is to export the project to Keil and use uVision as its free to use up to 32k program flash.

Hi Paul,
Using uVision is impossible with the free version because I need much more than 32k flash. The Mbed Studio uses the latest ARM compiler and should work as good as the online compiler. A am happy with the “bare-metal” result.
I am working with a Mac, using uVision means I need to boot a VM etc.